RATIOS and

PROPORTIONS


Proving Proportions

To Prove the Proportion Solution is Correct, Substitute the

Letter with the Number.




Proving the answer

3
:
4
::
X
:
8


24 = 4X


24 4 = X


6 = X


3
:
4
::
6
:
8


3
:
4
::
6
:
8
4 and 6 are the means


3
:
4
::
6
:
8
3 and 8 are the extremes


3 • 8 = 4 • 6


24 = 24





More Examples of Proving the Answers



3
:
10
::
6
:
X


3X = 60


X = 60 3


X = 20


3
:
10
::
6
:
20


3 • 20 = 10 • 6


60 = 60



* * * * *



5
:
15
::
X
:
3


15 = 15X


15 15 = X


1 = X


5
:
15
::
1
:
3


5 • 3 = 15 • 1


15 = 15



* * * * *



2
:
7
::
8
:
X


2X = 56


X = 56 2


X = 28


2
:
7
::
8
:
28


2 • 28 = 7 • 8


56 = 56